The present invention aims in particular to an electric shaver of the type having at least one cutter unit with a foil type upper cutter and a non-foil type lower cutter which perform a reciprocating relative movement with respect to each other when in use. In electric shavers of this type there is a general desire for adapting the cutter unit to the contour of the skin to be shaved. This is achieved by allowing a relative movement of the cutter unit with respect to the main housing or a handle of the electric shaver.
Various types of electric shavers are known allowing such a relative movement of the cutter unit with respect to the main housing. For example, EP 2 004 364 B1 discloses an electric shaver with a housing comprising a drive motor and a shaving head connected to the housing for pivotal movement about a pivot axis which is parallel to direction of the oscillating movement of cutters. The shaving head mounts two shaving systems, each comprised of an outer cutter and associated under cutters. The under cutters are adapted to be driven in an oscillatory linear motion relative to the outer cutter. The under cutters are mounted respectively on separate oscillatory elements in the shaving head. The oscillatory elements are each connected to the drive motor via drive elements and are driven in mutually opposite directions. One example uses a con-rod mounted to an eccentric portion of a drive shaft for driving an oscillatory bridge which in turn transmits the reciprocating translational movement to a lower cutter element. The con-rod comprises a pin engaging a slot in the oscillatory bridge which slot extends perpendicular to the horizontal (swiveling) axis. An alternative example uses pin-shaped oscillators which are each coupled via a joint pushrod to an oscillatory plate which in turn transmits the reciprocating translational movement to a lower cutter element. Both examples allow swiveling of the shaver head with respect to the shaver housing while transmitting a movement to the lower cutter element. Further electrical shavers allowing pivoting about a pivot axis parallel to direction of the oscillating movement of cutters are known from EP 0 618 853 B1 and EP 2 035 195 B1.
Further, EP 1 017 546 B1 shows a shaver with a shearing blade which is arranged in a pivotable head frame and cooperates with knives oscillating in the longitudinal direction of the shearing blades. The head frame is detachably connected with a base part including the drive. The head frame is designed in two parts comprising an external head part carrying the shearing blade and a part detachably fixed to the base part, wherein the external head part is connected with the head frame part detachably fixed to the base part, in a manner so as to be pivotable about an approximately central pivot axis extending transverse to the oscillation direction of the knives. Further examples of a shaver allowing pivoting of about an axis extending transverse to the oscillation direction of the knives are disclosed in EP 2 435 218 A1 and GB 22 66 070 A.
EP 1 161 325 B1 suggests an electric shaver with oscillating cutting knifes which move relative to a shearing blade. A shearing head carrying the shearing blade is driven by a drive unit to perform a gyration or tilting movement.
In RU 2 175 911 C a shaver of the type with rotating blades is described. A supporting ring is joined with a holder by means of cross like cardan-joint such that the supporting ring may perform a rocking motion in any direction relative to a cutting head. Further, EP 2 208 589 B1 discloses an electric shaver comprising a head part swingably attached to a body part. The head part includes a shaving portion having paired blades and a drive mechanism configured to drive at least one of the paired blades. An interposer is provided configured to support the head part on the body part swingably about a first swing axis and swingably about a second swing axis orthogonal to the first swing axis.
EP 1 728 603 B1 describes a shaver with a head portion and a main body grip portion which supports the head portion in a manner that the head portion can vertically float and tilt. Further, WO 03/026854 A1 suggests a reciprocation type electric shaver which comprises a main body block and a head block. The main body block has independently vertically movable head support members at a total of four places and head float springs for upwardly urging these head support members for floating. Upper ends of head support members on the main body block side are longitudinally turnably connected to rotary connecting portions at four places, respectively, around the transverse axis of the main body, thus allowing the head block to swing longitudinally with respect to the main body block.
Due to the requirement that the cutter element of the shaver has to be coupled to a drive unit for transmitting a driving force or movement, the degree of such a relative movement of the cutter unit with respect to the housing is facing constraints. It is accordingly an object of the present invention to propose an electric shaver of the type mentioned above which improves the ability of adaption to the contour of the skin to be shaved.